1. Technical Field
The present invention relates to a micro bio sensor and a method for manufacturing the micro bio sensor.
2. Related Art
In a field such as foods and drinks, drugs and medicines, and cosmetics, species of a microbe are identified and a total number of the species of the microbe is counted for the purpose of determining whether or not microbial contamination occurs.
As a conventional method for counting a total number of species of a microbe, for example hiochi bacterium, contained in a specimen, the following method is carried out. After a solution containing the microbe (hiochi bacterium) is added in a agar medium and then the agar medium is cultivated for a few days, a number of colonies produced in the agar medium is counted by a visual check or with a colony counter. And thereafter, the total number of the hiochi bacterium contained in the specimen is obtained by counting backward using the counted number of the colonies.
Further, for identifying species of a microbe, the following method is generally carried out. Namely, the method is carried out by preparing a medium which contains an additive that develops a predetermined color if colonies of a predetermined microbe are produced in an agar medium, adding a solution containing an unknown microbe to the medium, cultivating the medium for a few days, and identifying the microbe based on the developed color of the additive.
However, in the conventional methods for cultivating the microbe by using the agar medium, a considerably long time e.g. 24 to 120 hours is required for the cultivation. Further, various skills are required in preparing the medium, preparing the solution containing the unknown microbe, adding the solution containing the unknown microbe to the medium, studying cultural conditions, counting colonies and the like. Therefore, it is desired to develop a new method that can detect or measure a microbe more rapidly and easily than the conventional methods.
Under the circumstances, recently, there are proposed a detecting method using an electrochemical reaction or a gene, methods using an immune reaction or an emission of ATP and the like in order to identify a microbe.
However, in the detecting method using the electrochemical reaction or the gene, the methods using the immune reaction or the emission of ATP and the like, various skills are still required in pre-cultivation of the microbe or handling thereof. Further, these methods have problems such as detection sensitivity of the microbe, price of an apparatus to be used in these methods and the like. Therefore, these methods do not replace the conventional methods for cultivating the microbe using the agar medium as described above.
For these reasons, it is strongly desired to develop a method and a principle that are capable of detecting a microbe easily with a high sensitive for accomplishing high quality control of alcoholic beverages.
On the other hand, in a method for detecting a microbe based on changes in frequency that are caused by bonding the microbe to a surface of an electrode in a state that a voltage is applied between two electrodes, a method using a crystal oscillator in which an antimicrobial antibody is immobilized on a surface of an electrode is proposed. And one example thereof is disclosed in JP-A-62-64934. However, the method is not put into practical use due to low detection sensitivity to the microbe.
Further, a crystal oscillator-micro bio sensor in which an antimicrobial antibody is immobilized through protein A or protein G on a surface of an electrode for the purpose of improving detection sensitivity is proposed as disclosed in JP-A-2002-340766. This sensor is not appropriate in the purpose of detecting two or more species of a microbe concurrently.
Furthermore, a rapid detection device for detecting a microbe is proposed as disclosed in JP-A-2005-172680. The rapid detection device is provided with a base material comprised of substances that can specifically trap a desired microbe existing in a specimen. And the rapid detection device includes a means for optically detecting the desired microbe trapped on the base material. This device is also not appropriate in the purpose of detecting two or more species of the microbe concurrently.